/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package network;
/**
 * 简单数据库操作接口
 */
import java.sql.*;
import java.util.*;
public class Database
{
    private static Database baseDao = null;
    private List<Connection> idle = new ArrayList<Connection>(0);
    private Map<Thread, Connection> busy = new HashMap<Thread, Connection>(0);
    private Map<String, Connection> cache = new HashMap<String, Connection>(0);
    private String dialect = "ORACLE";

    /**
     * 读取配置文件加载数据库配置信息到Properties,创建一定数量的连接到连接池
     */
    private Database()
    {
        try
        {
            String driver = Config.db_driver;
            String url = Config.db_url+Config.db_name;
            String username = Config.db_username;
            String password = Config.db_password;
            int maxsize = Integer.parseInt(Config.db_max);
            try {
				Class.forName(driver).newInstance();
			} catch (InstantiationException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} catch (IllegalAccessException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
            for(int k = 0; k < maxsize; k++)
            {
                Connection conn = DriverManager.getConnection(url, username,
                        password);
                idle.add(conn);
            }
        }
        catch(ClassNotFoundException e)
        {
            e.printStackTrace();
        }
        catch(SQLException e)
        {
            e.printStackTrace();
        }
    }

    /**
     * 创建数据库操作接口
     *
     * @return 数据库操作接口BaseDao单例
     */
    public static Database getInstance()
    {
        if(null == baseDao)
        {
            baseDao = new Database();
        }
        return baseDao;
    }

    /**
     * 获得数据库连接
     *
     * @return 数据库连接
     */
    private synchronized Connection getConn()
    {
        Connection conn = null;
        try
        {
            if(idle.isEmpty())
            {
                wait();
            }
            conn = idle.get(0);
            busy.put(Thread.currentThread(), conn);
            idle.remove(0);
        }
        catch(InterruptedException e)
        {
            e.printStackTrace();
        }
        return conn;
    }

    /**
     * 无事务更新(不带参数)
     *
     * @param sql
     *            SQL语句 ："update table set price=200.00"
     * @return 受影响行数
     * @throws SQLException
     */
    public int update(String sql) throws Exception
    {
        int result = 0;
        Connection conn = null;
        PreparedStatement ps = null;
        try
        {
            conn = getConn();
            ps = conn.prepareStatement(sql);
            result = ps.executeUpdate();
        }
        catch(SQLException e)
        {
            throw e;
        }
        finally
        {
            closeAll(null, ps);
        }
        return result;
    }

    /**
     * 无事务更新(带参数)
     *
     * @param sql
     *            SQL语句 :"delete from table where id=?"
     * @param params
     *            参数对象数组 :new Object[]{参数1,参数2,...}
     * @return 受影响行数
     * @throws SQLException
     */
    public int update(String sql, Object[] params) throws SQLException
    {
        int result = 0;
        Connection conn = null;
        PreparedStatement ps = null;
        try
        {
            conn = getConn();
            ps = conn.prepareStatement(sql);
            for(int i = 0; i < params.length; i++)
            {
                ps.setObject(i + 1, params[i]);
            }
            result = ps.executeUpdate();
        }
        catch(SQLException e)
        {
            throw e;
        }
        finally
        {
            closeAll(null, ps);
        }
        return result;
    }

    /**
     * 在事务下更新(不带参数)
     *
     * @param transId
     *            事务ID
     * @param sql
     *            SQL语句 :"update table set price=200.00"
     * @return 受影响行数
     * @throws SQLException
     */
    public int update(String transId, String sql) throws SQLException
    {
        int result = 0;
        Connection conn = cache.get(transId);
        PreparedStatement ps = conn.prepareStatement(sql);
        result = ps.executeUpdate();
        return result;
    }

    /**
	 * 关闭所有对对象,归还链接到连接池
	 *
	 * @param rs
	 *            数据集对象
	 * @param ps
	 *            Ԥ命令对象
	 */
	private synchronized void closeAll(ResultSet rs, PreparedStatement ps)
	{
	    if(null != rs)
	    {
	        try
	        {
	            rs.close();
	        }
	        catch(Exception e)
	        {
	            e.printStackTrace();
	        }
	    }
	    if(null != ps)
	    {
	        try
	        {
	            ps.close();
	        }
	        catch(Exception e)
	        {
	            e.printStackTrace();
	        }
	    }
	    Connection conn = busy.get(Thread.currentThread());
	    if(null != conn)
	    {
	        idle.add(conn);
	        busy.remove(Thread.currentThread());
	        notify();
	    }
	}

	/**
     * 在事务下更新(带参数)
     *
     * @param transId
     *            事务ID
     * @param sql
     *            SQL语句 :"delete from table where id=?"
     * @param params
     *            参数对象数组 :new Object[]{参数1,参数2,...}
     * @return 受影响行数
     * @throws SQLException
     */
    public int update(String transId, String sql, Object[] params)
            throws SQLException
    {
        int result = 0;
        Connection conn = cache.get(transId);
        PreparedStatement ps = conn.prepareStatement(sql);
        for(int i = 0; i < params.length; i++)
        {
            ps.setObject(i + 1, params[i]);
        }
        result = ps.executeUpdate();
        return result;
    }

    /**
     * 非事务下批量更新
     *
     * @param sql
     *            SQL语句 :"insert into table(p1,p2,p3) values(?,?,?)"
     * @param params
     *            参数集合List<Object[]> 其中new Object[]{参数1,参数2,...}
     * @return 受影响行数
     * @throws SQLException
     */
    public int[] batchUpdate(String sql, List<Object[]> params)
            throws SQLException
    {
        int[] result = new int[params.size()];
        Connection conn = null;
        PreparedStatement ps = null;
        try
        {
            conn = getConn();
            conn.setAutoCommit(false);
            ps = conn.prepareStatement(sql);
            for(Object[] objects : params)
            {
                for(int i = 0; i < objects.length; i++)
                {
                    ps.setObject(i + 1, objects[i]);
                }
                ps.addBatch();
            }
            result = ps.executeBatch();
            conn.commit();
        }
        catch(SQLException e)
        {
            throw e;
        }
        finally
        {
            closeAll(null, ps);
        }
        return result;
    }

    /**
     * 在事务下批量更新
     *
     * @param transId
     *            事务ID
     * @param sql
     *            SQL语句 :"insert into table(p1,p2,p3) values(?,?,?)"
     * @param params
     *            参数集合List<Object[]> 其中new Object[]{参数1,参数2,...}
     * @return 受影响行数
     * @throws SQLException
     */
    public int[] batchUpdate(String transId, String sql, List<Object[]> params)
            throws SQLException
    {
        int[] result = new int[params.size()];

        Connection conn = cache.get(transId);
        PreparedStatement ps = conn.prepareStatement(sql);
        for(Object[] objects : params)
        {
            for(int i = 0; i < objects.length; i++)
            {
                ps.setObject(i + 1, objects[i]);
            }
            ps.addBatch();
        }
        result = ps.executeBatch();
        return result;
    }

    /**
     * 查询(不带参数)返回List<Map<k,v>>其中k:字段名小写,v:字段值
     *
     * @param sql
     *            SQL语句 :"select * from table"
     * @return 集合List<Map<k,v>> 其中k:字段名小写,v:字段值
     * @throws SQLException
     */
    public List<Map<String, Object>> query(String sql) throws SQLException
    {
        List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        try
        {
            conn = getConn();
            ps = conn.prepareStatement(sql);
            rs = ps.executeQuery();
            ResultSetMetaData rsmd = rs.getMetaData();
            int colCount = rsmd.getColumnCount();
            while(rs.next())
            {
                Map<String, Object> map = new HashMap<String, Object>();
                for(int i = 0; i < colCount; i++)
                {
                    String key = rsmd.getColumnName(i + 1).toLowerCase();
                    Object val = rs.getObject(i + 1) != null ? rs
                            .getObject(i + 1) : "";
                    map.put(key, val);
                }
                list.add(map);
            }
        }
        catch(SQLException e)
        {
            throw e;
        }
        finally
        {
            closeAll(rs, ps);
        }
        return list;
    }

    /**
     * 查询(不带参数)返回XML格式数据
     *
     * @param sql
     *            SQL语句 :"select * from table"
     * @return XML格式数据
     * @throws SQLException
     */
    public String queryXML(String sql) throws SQLException
    {
        List<Map<String, Object>> list = query(sql);
        return List2Xml(list.size(), list);
    }

    /**
     * 查询(不带参数)返回JSON格式数据
     *
     * @param sql
     *            SQL语句 :"select * from table"
     * @return JSON格式数据
     * @throws SQLException
     */
    public String queryJSON(String sql) throws SQLException
    {
        List<Map<String, Object>> list = query(sql);
        return List2Json(list.size(), list);
    }

    /**
     * 分页查询(不带参数)返回List<Map<k,v>>其中k:字段名小写,v:字段值
     *
     * @param sql
     *            SQL语句 :"select * from table"
     * @param currPage
     *            第几页
     * @param pageSize
     *            每页记录数
     * @return 集合List<Map<k,v>> 其中k:字段名小写,v:字段值
     * @throws SQLException
     */
    public List<Map<String, Object>> queryPager(String sql, int currPage,
            int pageSize) throws SQLException
    {
        String pageSql = getPageSql(sql, currPage, pageSize);
        System.out.println(pageSql);
        return query(pageSql);
    }

    /**
     * 分页查询(不带参数)返回XML格式数据
     *
     * @param sql
     *            SQL语句 :"select * from table"
     * @param currPage
     *            第几页
     * @param pageSize
     *            每页记录数
     * @return XML格式数据
     * @throws SQLException
     */
    public String queryXMLPager(String sql, int currPage, int pageSize)
            throws SQLException
    {
        int count = total(sql);
        String pageSql = getPageSql(sql, currPage, pageSize);
        List<Map<String, Object>> list = query(pageSql);
        return List2Xml(count, list);
    }

    /**
     * 分页查询(不带参数)返回JSON格式数据
     *
     * @param sql
     *            SQL语句 :"select * from table"
     * @param currPage
     *            第几页
     * @param pageSize
     *            每页记录数
     * @return JSON格式数据
     * @throws SQLException
     */
    public String queryJSONPager(String sql, int currPage, int pageSize)
            throws SQLException
    {
        int count = total(sql);
        String pageSql = getPageSql(sql, currPage, pageSize);
        List<Map<String, Object>> list = query(pageSql);
        return List2Json(count, list);
    }

    /**
     * 查询(带参数)返回List<Map<k,v>>其中k:字段名小写,v:字段值
     *
     * @param sql
     *            SQL语句 :"select * from table where id = ?"
     * @param params
     *            参数对象数组 :new Object[]{参数1,参数2,...}
     * @return 集合List<Map<k,v>> 其中k:字段名小写,v:字段值
     * @throws SQLException
     */
    public List<Map<String, Object>> query(String sql, Object[] params)
            throws SQLException
    {
        List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        try
        {
            conn = getConn();
            ps = conn.prepareStatement(sql);
            for(int i = 0; i < params.length; i++)
            {
                ps.setObject(i + 1, params[i]);
            }
            rs = ps.executeQuery();
            ResultSetMetaData rsmd = rs.getMetaData();
            int colCount = rsmd.getColumnCount();
            while(rs.next())
            {
                Map<String, Object> map = new HashMap<String, Object>();
                for(int i = 0; i < colCount; i++)
                {
                    String key = rsmd.getColumnName(i + 1).toLowerCase();
                    Object val = rs.getObject(i + 1) != null ? rs
                            .getObject(i + 1) : "";
                    map.put(key, val);
                }
                list.add(map);
            }
        }
        catch(SQLException e)
        {
            throw e;
        }
        finally
        {
            closeAll(rs, ps);
        }
        return list;
    }

    /**
     * 查询(带参数)返回XML格式数据
     *
     * @param sql
     *            SQL语句 :"select * from table where id = ?"
     * @param params
     *            参数对象数组 :new Object[]{参数1,参数2,...}
     * @return XML格式数据
     * @throws SQLException
     */
    public String queryXML(String sql, Object[] params) throws SQLException
    {
        List<Map<String, Object>> list = query(sql, params);
        return List2Xml(list.size(), list);
    }

    /**
     * 查询(带参数)返回XML格式数据
     *
     * @param sql
     *            SQL语句 :"select * from table where id = ?"
     * @param params
     *            参数对象数组 :new Object[]{参数1,参数2,...}
     * @return XML格式数据
     * @throws SQLException
     */
    public String queryJSON(String sql, Object[] params) throws SQLException
    {
        List<Map<String, Object>> list = query(sql, params);
        return List2Json(list.size(), list);
    }

    /**
     * 分页查询(带参数)返回List<Map<k,v>>其中k:字段名小写,v:字段值
     *
     * @param sql
     *            SQL语句 :"select * from table where id = ?"
     * @param params
     *            参数对象数组 :new Object[]{参数1,参数2,...}
     * @param currPage
     *            第几页
     * @param pageSize
     *            每页记录数
     * @return 集合List<Map<k,v>> 其中k:字段名小写,v:字段值
     * @throws SQLException
     */
    public List<Map<String, Object>> queryPager(String sql, Object[] params,
            int currPage, int pageSize) throws SQLException
    {
        String pageSql = getPageSql(sql, currPage, pageSize);
        return query(pageSql);
    }

    /**
     * 分页查询(带参数)返回XML格式数据
     *
     * @param sql
     *            SQL语句 :"select * from table where id = ?"
     * @param params
     *            参数对象数组 :new Object[]{参数1,参数2,...}
     * @param currPage
     *            第几页
     * @param pageSize
     *            每页记录数
     * @return XML格式数据
     * @throws SQLException
     */
    public String queryXMLPager(String sql, Object[] params, int currPage,
            int pageSize) throws SQLException
    {
        int count = total(sql, params);
        String pageSql = getPageSql(sql, currPage, pageSize);
        List<Map<String, Object>> list = query(pageSql, params);
        return List2Xml(count, list);
    }

    /**
     * 分页查询(带参数)返回JSON格式数据
     *
     * @param sql
     *            SQL语句 :"select * from table where id = ?"
     * @param params
     *            参数对象数组 :new Object[]{参数1,参数2,...}
     * @param currPage
     *            第几页
     * @param pageSize
     *            每页记录数
     * @return JSON格式数据
     * @throws SQLException
     */
    public String queryJSONPager(String sql, Object[] params, int currPage,
            int pageSize) throws SQLException
    {
        int count = total(sql, params);
        String pageSql = getPageSql(sql, currPage, pageSize);
        List<Map<String, Object>> list = query(pageSql, params);
        return List2Json(count, list);
    }

    /**
     * 单值查询(不带参数)
     *
     * @param sql
     *            SQL语句 :"select name from table"
     * @return 单值
     * @throws SQLException
     */
    public String scalar(String sql) throws SQLException
    {
        String res = null;
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        try
        {
            conn = getConn();
            ps = conn.prepareStatement(sql);
            rs = ps.executeQuery();
            if(rs.next())
            {
                res = rs.getObject(1).toString();
            }
        }
        catch(SQLException e)
        {
            throw e;
        }
        finally
        {
            closeAll(rs, ps);
        }
        return res;
    }

    /**
     * 查询总记录数(不带参数)
     *
     * @param sql
     *            SQL语句 :"select count(*) from table"
     * @param params
     *            参数对象数组 :new Object[]{参数1,参数2,...}
     * @return 总记录数
     * @throws SQLException
     */
    public int count(String sql) throws SQLException
    {
        int count = Integer.valueOf(scalar(sql));
        return count;
    }

    /**
     * 单值查询(带参)
     *
     * @param sql
     *            SQL语句 :"select name from table where id=?"
     * @param params
     *            参数对象数组 :new Object[]{参数1,参数2,...}
     * @return 单值
     * @throws SQLException
     */
    public String scalar(String sql, Object[] params) throws SQLException
    {
        String res = null;
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        try
        {
            conn = getConn();
            ps = conn.prepareStatement(sql);
            for(int i = 0; i < params.length; i++)
            {
                ps.setObject(i + 1, params[i]);
            }
            rs = ps.executeQuery();
            if(rs.next())
            {
                res = rs.getObject(1).toString();
            }
        }
        catch(SQLException e)
        {
            throw e;
        }
        finally
        {
            closeAll(rs, ps);
        }
        return res;
    }

    /**
     * 查询总记录数(带参数)
     *
     * @param sql
     *            SQL语句 :"select count(*) from table where id=?"
     * @param params
     *            参数对象数组 :new Object[]{参数1,参数2,...}
     * @return 总记录数
     * @throws SQLException
     */
    public int count(String sql, Object[] params) throws SQLException
    {
        int count = Integer.valueOf(scalar(sql, params));
        return count;
    }

    /**
     * 执行存储过程
     *
     * @param spName
     *            存储过程
     * @param params
     *            存储过程参数对象数组 :new Object[]{参数1,参数2,...}
     * @param outParamNum
     *            输出参数个数
     * @return
     * @throws SQLException
     */
    public String[] execProc(String procName, Object[] params, int outParamNum)
            throws SQLException
    {
        String[] ret = new String[outParamNum];
        Connection conn = null;
        CallableStatement cs = null;
        try
        {
            conn = getConn();
            int inParamNum = (null != params) ? params.length : 0;
            String pSql = getPSql(procName, inParamNum, outParamNum);
            cs = conn.prepareCall(pSql);
            for(int i = 0; i < inParamNum; i++)
            {
                cs.setObject(i + 1, params[i]);
            }
            for(int k = 1; k <= outParamNum; k++)
            {
                cs.registerOutParameter(inParamNum + k, Types.VARCHAR);
            }
            cs.executeQuery();
            for(int k = 1; k <= outParamNum; k++)
            {
                ret[k - 1] = cs.getString(inParamNum + k);
            }
        }
        catch(SQLException e)
        {
            throw e;
        }
        finally
        {
            closeAll(null, cs);
        }
        return ret;
    }

    /**
     * 得到存储过程语句
     *
     * @param procName
     *            存储过程
     * @param inParamNum
     *            输入参数个数
     * @param outParamNum
     *            输出参数个数
     * @return
     * @throws SQLException
     */
    private String getPSql(String procName, int inParamNum, int outParamNum)
            throws SQLException
    {
        StringBuffer sb = new StringBuffer();
        sb.append("{call ").append(procName);
        int paramCount = inParamNum + outParamNum;
        if(paramCount > 0)
        {
            sb.append("(");
            for(int i = 0; i < paramCount; i++)
            {
                sb.append("?");
                if(i != paramCount - 1)
                {
                    sb.append(",");
                }
            }
            sb.append(")");
        }
        sb.append("}");
        return sb.toString();
    }

    /**
     * 开始事务
     *
     * @return 事务ID
     */
    public String beginTrans()
    {
        String transId = null;
        try
        {
            Connection conn = getConn();
            conn.setAutoCommit(false);
            transId = UUID.randomUUID().toString();
            cache.put(transId, conn);
        }
        catch(SQLException e)
        {
            e.printStackTrace();
        }
        return transId;
    }

    /**
     * 事务提交
     *
     * @param transId
     *            事务ID
     */
    public void commitTrans(String transId)
    {
        Connection conn = null;
        try
        {
            conn = cache.get(transId);
            conn.commit();
        }
        catch(SQLException e)
        {
            e.printStackTrace();
        }
        finally
        {
            closeAll(null, null);
            cache.remove(conn);
        }
    }

    /**
     * 事务回滚
     *
     * @param transId
     *            事务ID
     */
    public void rollbackTrans(String transId)
    {
        Connection conn = null;
        try
        {
            conn = cache.get(transId);
            conn.rollback();
            cache.remove(conn);
        }
        catch(SQLException e)
        {
            e.printStackTrace();
        }
        finally
        {
            closeAll(null, null);
            cache.remove(conn);
        }
    }

    private String List2Json(int count, List<Map<String, Object>> list)
            throws SQLException
    {
        StringBuffer sb = new StringBuffer();
        if(count > 0)
        {
            int len1 = list.size();
            sb.append("{total:").append(count).append(",root:[");
            for(int i = 0; i < len1; i++)
            {
                sb.append("{");
                Map<String, Object> map = list.get(i);
                String[] keys = map.keySet().toArray(new String[0]);
                int len2 = keys.length;
                for(int k = 0; k < len2; k++)
                {
                    sb.append(keys[k]).append(":").append("'").append(
                            map.get(keys[k])).append("'");
                    if(k != len2 - 1)
                    {
                        sb.append(",");
                    }
                }
                sb.append("}");
                if(i != len1 - 1)
                {
                    sb.append(",");
                }
            }
            sb.append("]}");
        }
        return sb.toString();
    }

    private String List2Xml(int count, List<Map<String, Object>> list)
            throws SQLException
    {
        StringBuffer sb = new StringBuffer(
                "<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
        sb.append("<list>");
        if(count > 0)
        {
            sb.append("<total>").append(count).append("</total>");
            for(Map<String, Object> map : list)
            {
                sb.append("<item>");
                for(Map.Entry<String, Object> entry : map.entrySet())
                {
                    sb.append("<").append(entry.getKey()).append(">");
                    sb.append(entry.getValue());
                    sb.append("</").append(entry.getKey()).append(">");
                }
                sb.append("</item>");
            }
        }
        sb.append("</list>");
        return sb.toString();
    }

    private int total(String sql) throws NumberFormatException, SQLException
    {
        StringBuffer countSql = new StringBuffer(0);
        int fromIndex = sql.toLowerCase().indexOf("from");
        countSql.append("select count(*) ").append(sql.substring(fromIndex));
        return Integer.valueOf(scalar(countSql.toString()));
    }

    private int total(String sql, Object[] params)
            throws NumberFormatException, SQLException
    {
        StringBuffer countSql = new StringBuffer(0);
        int fromIndex = sql.toLowerCase().indexOf("from");
        countSql.append("select count(*) ").append(sql.substring(fromIndex));
        return Integer.valueOf(scalar(countSql.toString(), params));
    }

    private String getPageSql(String sql, int currPage, int pageSize)
    {
        StringBuffer pageSql = new StringBuffer(0);
        if("oracle".equalsIgnoreCase(dialect))
        {
            pageSql.append("SELECT * FROM(SELECT FA.*, ROWNUM RN FROM (");
            pageSql.append(sql).append(")as a, FA WHERE ROWNUM <= ");
            pageSql.append(currPage * pageSize).append(")as b WHERE RN >= ").append(
                    (currPage - 1) * pageSize + 1);
        }
        if("mysql".equalsIgnoreCase(dialect))
        {
            pageSql.append(sql).append(" limit ").append(
                    (currPage - 1) * pageSize).append(",").append(pageSize);
        }
        return pageSql.toString();
    }
    public void insert(String sql){

        Connection conn = null;
        PreparedStatement ps = null;
        try
        {
            conn = getConn();
            ps = conn.prepareStatement(sql);
            ps.executeUpdate();
        }catch(SQLException e){
        	e.printStackTrace();
        }
        finally
        {
            closeAll(null, ps);
        }
    }
    /**
     * 测试BaseDao
     *
     * @param args

    public static void main(String[] args)
    {
        try
        {
        	Database dao = Database.getInstance();
            String sql0 = "INSERT INTO sina.relation (uid, fid, fname) VALUES ('1912958980','1778830754','黄宇KaldrArt')";
            String sql = "select * from relation";
            dao.insert(sql0);

        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }  */
}